An air conditioning system, such as a vapor-compression system, typically has a compressor, a condenser, an evaporator, and/or exhaust fans. During a typical cooling cycle, the compressor can compress refrigerant vapor to high-pressure high-temperature refrigerant vapor. The high-pressure high-temperature refrigerant vapor can release heat in the condenser and become a liquid refrigerant. The liquid refrigerant can then flow to the evaporator through an expansion valve, and transform to the vapor state as the liquid refrigerant absorbs heat. The vaporized refrigerant from the evaporator can then circulate back to the compressor to be compressed in the compressor.
There are several types of compressors for the vapor-compression type of air conditioning system, such as reciprocating compressors, scroll compressors, screw compressors and centrifugal compressors. These types of compressors are typically powered by electric motors or gas turbines. When in operation, the compressors can generate vibration and noise. For example, in a chiller system, the screw compressor is one of the main sources of vibration and noise.
In the vapor-compression type of air conditioning system, the pressure of the refrigerant vapor after the refrigerant vapor is compressed by the compressor can be relatively high, for example up to about 350 psi. Refrigerant lines, such as pipes carrying the high pressure refrigerant vapor are generally configured to be able to withstand at least two times the pressure of the compressed refrigerant vapor. The pipes therefore generally are rigid. The rigid pipes can not only create noise, but also transmit vibration of one component, such as the compressor, to other parts of the air conditioning system, such as the refrigerant line(s) and/or the components such as an oil separator of the air conditioning system, causing operation noise of the air conditioning system. In transmitting the vibration, rigid pipes themselves can radiate sound as well.